A simple project checker that can search whole projects or individual
classes or methods for various problems that may cause build problems,
such as:
- inconsistent/messed up project definition class
- method code problems
NOTE: this is not a lint. It only checks for inconsitent configuration
(projectDefinition class data vs. real data) and compilability (stc limitations).
NOTE: Not yet finished. This code is meant as a single central entry for all the
source code management tools like SCM Utilities, NewSystemBrowser ets. That code
will be refactored later once this tool prooves itself useful and mature enough.
[instance variables:]
[class variables:]

Checks whether all extensions listed in #extensionMethodNames are present
and if all extension methods are listed.
Also check if any regular or extension method is also listed in some other package
(which may happen after a move, if the original package was not updated)